Antimicrobial activities and chemical compositions of Chrysophyllum cainito (star apple) fruit

Abstract

The pulp and seed of Chrysophyllum cainito was analyzed for its antimicrobial potentials, microbial profile, anti-nutrients and nutrients using standard methods. The pulp and seed showed varying levels of antimicrobial activities against some clinical isolates such as Escherichia coli and species of Salmonella, Staphylococcus, Pseudomonas, Aspergillus, Candida> and Penicillium. The microbial count of the fruits ranged from 1.0 × 10⁹ to 2.4 × 10¹⁰ for total aerobic plate count, 1.0 × 10⁷ to 2.0 × 10⁷ for fungal count and 1.0 × 10⁸ to 1.2 × 10⁹ for coliform count. The identities of the normal flora on the surfaces and pulp of healthy fruits and of spoilage organisms were confirmed to include species of Bacillus, Corynebacterium, Staphylococcus, Micrococcus, Acinetobacter, Enterococcus, and Pseudomonas. The fungal isolates include species of Rhizopus, Aspergillus, Penicillum and Saccharomyces. The high microbial counts and their presence, portends serious health implication. Aspergillus and Penicillium species produces mycotoxins involved in mycotoxicosis of humans and animals. Staphylococcus and Bacillus species produce potent toxins implicated in food borne illnesses, while the presence of Enterococcus indicates feacal contamination. Varying concentrations of phytochemicals such as saponin, flavonoids, tannin, steroid and cardiac glycoside were detected. Vitamins such as vitamin A (0.027 to 0.089 mg) and vitamin C (10.00 to 43.54 mg) were also present. Minerals such as calcium, magnesium, phosphorus, potassium and sodium were present at concentrations of 37.0, 5.0, 8.0, 38.0 and 21.0 mg respectively, for the pulp extracts. The proximate composition of star apple consists of protein (1.96 to 4.63 g), moisture (56.04 to 75.90 g), fat (0.88 to 15.81 g), fibre (2.31 to 4.19 g), ash (0.56 to 0.84 g) and carbohydrate (18.39 to 78.49 g). Chrysophyllum cainito holds great potentials as an antimicrobial agent for chemotherapeutic medicine and it is a rich source of nutrient and phytochemicals.

Keywords: Chrysophyllum cainito, anti-nutritive composition, antimicrobial activity.